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Silastic implant pharyngoplasty: Radiographic planning and evaluation
SILASTIC IMPLANT PHARYNGOPLASTV: EADIOGRAPHIC PLANNING AND EVALUATION By D. M. EVANS, F.R.C.S.
and G. M.
ARDRAN,F.R.C.P.,
F.R.C.R.
Department of Plastic Surgery, Churchill Hospital, Oxford and Nujield Institute for Medical Research, University of Oxford CORRECTING
palato-pharyngeal incompetence by advancing the posterior pharyngeal wall is not a new idea and the subject has been well reviewed by Blocksma (rg63,rg7r) who was the first to implant a piece of Mastic1 block for this purpose. Brauer (1973) believing that the rigidity of Mastic block was the cause of extrusion of some implants, reported 26 patients in whom he had inserted Silastic gel “pillows” wrapped around with Dacron; only I was extruded and of the remaining patients all but I had speech improvement. Failure to improve speech by this method might be due to a number of factors, including immobility of a scarred soft palate, inadequate protrusion of the posterior pharyngeal wall in relation to the gap to be overcome, or incorrect vertical placing of the
FIG. I. Lateral X-rays on saying EE, (a) before and (b) after implant pharyngoplasty, in a patient with a submucous cleft. The implant is at a good level, and the soft palate rises to the same level in both films, so that the degree of narrowing reflects the thickness of the implant. The patient has a fair result.
1 Dow Corning. 206
SILASTIC IMPLANT
PHARYNGOPLASTY
207
FIG. 2. (a) and (b). Before and after implant pharyngoplasty in the only patient with a repaired cleft The implant is in good relationship with the soft palate who had a good result following this operation. palate, but above the arch of the atlas.
implant. In our experience the first constitutes a contraindication to the method, since its use in patients with repaired palatal clefts has rarely been successful. All of Brauer’s patients had a preoperative gap of 6 mm or less on phonation and in our opinion a 5 mm advancement is all that can be expected. This is one reason for preoperative lateral radiography of the region. Another is to find the precise level at which the implant is to be inserted. This point has been neglected in previous writings which usually just recommend high insertion, but this is not always desirable, as will be shown. MATERIAL
AND METHODS
Fifteen patients with palato-pharyngeal incompetence who had implants of either Silastic block or Mastic sponge have been studied by pre- and at least 3 months postoperative X-rays and pre- and postoperative speech assessment. Four of the patients had repaired cleft palates while the others had such conditions as a submucous cleft, a congenital large pharynx, or a hemiparesis of the soft palate. Several other patients with previous pharyngeal scarring extruded their implants, and these are not included in this study. One or two ml of barium suspension is Technique of X-ray examination. introduced into one or both nostrils with the patient supine, with instructions not to
208
BRITISH
JOURNAL
OF PLASTIC
SURGERY
FIG. 3. (a) and (b). Before and after implant pharyngoplasty, in a patient with nasal escape following repair of a postalveolar cleft. The implant (visible as a soft shadow) is at the level of the arch of the atlas, but low in relation to the soft palate and speech was not improved.
swallow; with time and appropriate positioning it coats the upper surface of the soft palate and the posterior pharyngeal wall. An erect lateral radiograph is taken, centred on the soft palate, with the head and neck in the true lateral position. A metal rod, notched in centimetres, is held in the mouth in the midline to give a basis for measurement; the patient is breathing quietly. The examination is repeated without the metal marker while the patient is saying EE and SS. Lateral tine-fluorograms are next made saying EE and SS, counting 4-5-6-7, and swallowing a mouthful of barium suspension. Operation. The technique used has been adequately described by Blocksma (1963), Brauer (1973) and Kaplan et ~1. (1974). Size and position of implant. The reduction in gap is always less than the implant thickness; on average, it was just under half of the thickness but there were variations depending on the position of the implant. Thus: When the implant was too low for the soft palate to meet it (6 cases), the average in gap reduction was only + of the implant thickness; When the implant was at the right level (8 cases) the average reduction was 3 of the thickness. The remaining patient had a gap reduction of 14 times the implant thickness because of improved soft palate function.
SILASTIC
FIG. 4. After implant pharyngoplasty :, _“...,^^.,.. _L,._~ :- _,J..*:.... I^ -l__
IMPLANT
PHARYNGOPLASTY
in a
209
Foportion.
! I
The implant
___.__& I__
FIG. 5. X-rays taken while saying EE. (a) Preoperative, (b) 6 months postoperatively, and (c) 6 years postoperatively. This patient had palatopharyngeal dis~~~~rt$+,Land was classed as a P o‘W.:n,
210
BRITISH
JOURNAL
OF PLASTIC
SURGERY
The implant is not visible in (b) and the Fig. 6. (a) and (b). Before and after implant pharyngoplasty. soft tissue shadow is caused by the ear lobe. The Passavant’s ridge has been lost after operation and this patient’s nasal escape has not been improved.
The effectiveness of the implant depended to some extent on the relative levels of the arch of the atlas and the soft palate during elevation. If they are at the same level and the implant is placed on the arch the greatest benefit can be expected (Fig. I). In most cases this was not so. Figure 2 illustrates a case where the soft palate was above the arch of the atlas, and the implant was also placed above the arch, producing a prominence at the correct level although losing the benefit of the arch. This patient’s speech was much improved. Where the soft palate was high and the implant was placed on the arch, there was no improvement in speech (Fig. 3). Figure 4 shows a low placed palate, with the implant also inserted low, giving some improvement in speech. In general there was a tendency to insert the implants too low but in the odd case below the arch of the atlas may be the optimum site. Improvement in speech. Eleven of the patients had improved speech and some achieved normal or near normal speech. While the series is too small for statistical analysis we agree with other authors that the speech improvement after pharyngeal implants is greatest when the soft palate is still mobile and preferably unscarred, when the preoperative gap is less than about 5 mm and the position of the implant is at the site where the soft palate will impinge against it during speech. The patient’s determination is also important and continuing improvement may be seen (Fig. 5).
SILASTIC
IMPLANT
PHARYNGOPLASTY
211
Loss of Passavant’s ridge. One patient who had a prominent Passavant’s ridge lost this after the implant. Although the implant protruded the pharyngeal wall almost as far as the previous ridge, the contractile element was lost and there was no improvement in speech (Fig. 6). DISCUSSION Since no improvement in speech was produced by Mastic implant pharyngoplasty when the gap was wider than 5 mm, this is now accepted as the upper limit for the procedure, and its use is not recommended in the presence of palatal or pharyngeal scarring. Our present technique is to prepare an individual implant in advance for each patient as follows: After studying the X-rays, an exact replica of the implant is made in wax about twice the thickness of the gap on EE and with a smoothly curved anterior surface. The greatest thickness can be placed on one side if the gap is asymmetrical as in I patient with hemipalatal paralysis. Nasopharyngeal endoscopy might be of value in obtaining an exact transverse contour. The wax model is invested in plaster and cast in Silastic elastomer 382; a pinch of fine tantalum powder can be added with the stannous actuate catalyst to add radio-opacity. The implant is inserted at a level determined preoperatively by lateral X-rays, using the arch of the atlas as a reference point. With more careful selection and planning, better results should be attainable from this simple, quick operation which causes the least irreversible anatomical disturbance of all operations for palato-pharyngeal incompetence.
We thank Mews J. H. F. Batstone and T. J. S. Patterson, whosepatients we have studied, Mr P. K. B. Davis, who operated on some of the patients, Miss Susan Mills for advice on speech assessment,and Mr Stanley Ashington for photographic reproductions. REFERENCES BLOCKSMA,R. (1963). Correction of velopharyngeal insufficiency by silastic pharyngeal implant. Plasticand Reconstructive Surgey, 31, 268. BLOCKSMA,R. (1971). Implants in posterior pharynx, in “Cleft Lip and Palate”, edited by Grabb, W. C., Rosenstein, S. W. and Bzoch, R., p. 471. Boston: Little Brown and Company. BRAUER,R. 0. (1973). Retropharyngeal implantation of silicone gel pillows for veloPlasticand Reconstructive Surgey, 51, 254. pharyngeal incompetence. KAPLAN, E. N., MINAMI, R. T. and WV, G. (1974). Palatopharyngeal incompetence, in “Reviews in Plastic Surgery”, edited by Saad, M. N. and Lichtveld, P., p. 292. Amsterdam: Excerpta Medica.
and G. M.
ARDRAN,F.R.C.P.,
F.R.C.R.
Department of Plastic Surgery, Churchill Hospital, Oxford and Nujield Institute for Medical Research, University of Oxford CORRECTING
palato-pharyngeal incompetence by advancing the posterior pharyngeal wall is not a new idea and the subject has been well reviewed by Blocksma (rg63,rg7r) who was the first to implant a piece of Mastic1 block for this purpose. Brauer (1973) believing that the rigidity of Mastic block was the cause of extrusion of some implants, reported 26 patients in whom he had inserted Silastic gel “pillows” wrapped around with Dacron; only I was extruded and of the remaining patients all but I had speech improvement. Failure to improve speech by this method might be due to a number of factors, including immobility of a scarred soft palate, inadequate protrusion of the posterior pharyngeal wall in relation to the gap to be overcome, or incorrect vertical placing of the
FIG. I. Lateral X-rays on saying EE, (a) before and (b) after implant pharyngoplasty, in a patient with a submucous cleft. The implant is at a good level, and the soft palate rises to the same level in both films, so that the degree of narrowing reflects the thickness of the implant. The patient has a fair result.
1 Dow Corning. 206
SILASTIC IMPLANT
PHARYNGOPLASTY
207
FIG. 2. (a) and (b). Before and after implant pharyngoplasty in the only patient with a repaired cleft The implant is in good relationship with the soft palate who had a good result following this operation. palate, but above the arch of the atlas.
implant. In our experience the first constitutes a contraindication to the method, since its use in patients with repaired palatal clefts has rarely been successful. All of Brauer’s patients had a preoperative gap of 6 mm or less on phonation and in our opinion a 5 mm advancement is all that can be expected. This is one reason for preoperative lateral radiography of the region. Another is to find the precise level at which the implant is to be inserted. This point has been neglected in previous writings which usually just recommend high insertion, but this is not always desirable, as will be shown. MATERIAL
AND METHODS
Fifteen patients with palato-pharyngeal incompetence who had implants of either Silastic block or Mastic sponge have been studied by pre- and at least 3 months postoperative X-rays and pre- and postoperative speech assessment. Four of the patients had repaired cleft palates while the others had such conditions as a submucous cleft, a congenital large pharynx, or a hemiparesis of the soft palate. Several other patients with previous pharyngeal scarring extruded their implants, and these are not included in this study. One or two ml of barium suspension is Technique of X-ray examination. introduced into one or both nostrils with the patient supine, with instructions not to
208
BRITISH
JOURNAL
OF PLASTIC
SURGERY
FIG. 3. (a) and (b). Before and after implant pharyngoplasty, in a patient with nasal escape following repair of a postalveolar cleft. The implant (visible as a soft shadow) is at the level of the arch of the atlas, but low in relation to the soft palate and speech was not improved.
swallow; with time and appropriate positioning it coats the upper surface of the soft palate and the posterior pharyngeal wall. An erect lateral radiograph is taken, centred on the soft palate, with the head and neck in the true lateral position. A metal rod, notched in centimetres, is held in the mouth in the midline to give a basis for measurement; the patient is breathing quietly. The examination is repeated without the metal marker while the patient is saying EE and SS. Lateral tine-fluorograms are next made saying EE and SS, counting 4-5-6-7, and swallowing a mouthful of barium suspension. Operation. The technique used has been adequately described by Blocksma (1963), Brauer (1973) and Kaplan et ~1. (1974). Size and position of implant. The reduction in gap is always less than the implant thickness; on average, it was just under half of the thickness but there were variations depending on the position of the implant. Thus: When the implant was too low for the soft palate to meet it (6 cases), the average in gap reduction was only + of the implant thickness; When the implant was at the right level (8 cases) the average reduction was 3 of the thickness. The remaining patient had a gap reduction of 14 times the implant thickness because of improved soft palate function.
SILASTIC
FIG. 4. After implant pharyngoplasty :, _“...,^^.,.. _L,._~ :- _,J..*:.... I^ -l__
IMPLANT
PHARYNGOPLASTY
in a
209
Foportion.
! I
The implant
___.__& I__
FIG. 5. X-rays taken while saying EE. (a) Preoperative, (b) 6 months postoperatively, and (c) 6 years postoperatively. This patient had palatopharyngeal dis~~~~rt$+,Land was classed as a P o‘W.:n,
210
BRITISH
JOURNAL
OF PLASTIC
SURGERY
The implant is not visible in (b) and the Fig. 6. (a) and (b). Before and after implant pharyngoplasty. soft tissue shadow is caused by the ear lobe. The Passavant’s ridge has been lost after operation and this patient’s nasal escape has not been improved.
The effectiveness of the implant depended to some extent on the relative levels of the arch of the atlas and the soft palate during elevation. If they are at the same level and the implant is placed on the arch the greatest benefit can be expected (Fig. I). In most cases this was not so. Figure 2 illustrates a case where the soft palate was above the arch of the atlas, and the implant was also placed above the arch, producing a prominence at the correct level although losing the benefit of the arch. This patient’s speech was much improved. Where the soft palate was high and the implant was placed on the arch, there was no improvement in speech (Fig. 3). Figure 4 shows a low placed palate, with the implant also inserted low, giving some improvement in speech. In general there was a tendency to insert the implants too low but in the odd case below the arch of the atlas may be the optimum site. Improvement in speech. Eleven of the patients had improved speech and some achieved normal or near normal speech. While the series is too small for statistical analysis we agree with other authors that the speech improvement after pharyngeal implants is greatest when the soft palate is still mobile and preferably unscarred, when the preoperative gap is less than about 5 mm and the position of the implant is at the site where the soft palate will impinge against it during speech. The patient’s determination is also important and continuing improvement may be seen (Fig. 5).
SILASTIC
IMPLANT
PHARYNGOPLASTY
211
Loss of Passavant’s ridge. One patient who had a prominent Passavant’s ridge lost this after the implant. Although the implant protruded the pharyngeal wall almost as far as the previous ridge, the contractile element was lost and there was no improvement in speech (Fig. 6). DISCUSSION Since no improvement in speech was produced by Mastic implant pharyngoplasty when the gap was wider than 5 mm, this is now accepted as the upper limit for the procedure, and its use is not recommended in the presence of palatal or pharyngeal scarring. Our present technique is to prepare an individual implant in advance for each patient as follows: After studying the X-rays, an exact replica of the implant is made in wax about twice the thickness of the gap on EE and with a smoothly curved anterior surface. The greatest thickness can be placed on one side if the gap is asymmetrical as in I patient with hemipalatal paralysis. Nasopharyngeal endoscopy might be of value in obtaining an exact transverse contour. The wax model is invested in plaster and cast in Silastic elastomer 382; a pinch of fine tantalum powder can be added with the stannous actuate catalyst to add radio-opacity. The implant is inserted at a level determined preoperatively by lateral X-rays, using the arch of the atlas as a reference point. With more careful selection and planning, better results should be attainable from this simple, quick operation which causes the least irreversible anatomical disturbance of all operations for palato-pharyngeal incompetence.
We thank Mews J. H. F. Batstone and T. J. S. Patterson, whosepatients we have studied, Mr P. K. B. Davis, who operated on some of the patients, Miss Susan Mills for advice on speech assessment,and Mr Stanley Ashington for photographic reproductions. REFERENCES BLOCKSMA,R. (1963). Correction of velopharyngeal insufficiency by silastic pharyngeal implant. Plasticand Reconstructive Surgey, 31, 268. BLOCKSMA,R. (1971). Implants in posterior pharynx, in “Cleft Lip and Palate”, edited by Grabb, W. C., Rosenstein, S. W. and Bzoch, R., p. 471. Boston: Little Brown and Company. BRAUER,R. 0. (1973). Retropharyngeal implantation of silicone gel pillows for veloPlasticand Reconstructive Surgey, 51, 254. pharyngeal incompetence. KAPLAN, E. N., MINAMI, R. T. and WV, G. (1974). Palatopharyngeal incompetence, in “Reviews in Plastic Surgery”, edited by Saad, M. N. and Lichtveld, P., p. 292. Amsterdam: Excerpta Medica.